Pierre tanvez



P. TANVEZ.

GRINDING MILL.

Patented Nov. 21, l882 F/a/ i,

(No Mpdel.)

UNITED STATES PATENT EErcE.

I PIERRE TANVEZ, OF GUINGAMP, FRANCE.

G RINDING-NIILL.

SPECIFICATION forming part of Letters Patent No. 267,763, dated November 21, 1882.

Application tiled June 13,1881. (No modcL) Patented in France April 28,1879. No. 130,288; in England May 11, 1880, No. 1,928; in Belgium May 11, 1880, No. 51,428; in Austria May 22, 1880, No. 17,874; in Spain May 24, 1880, No. 828, and in Italy May 24, 1880,

To all whom 'it may concern:

Be it known that I, PIERRE TANvEz, of Guingamp, in the Republic of France, have invented a new and useful Improvement in Grinding-Mills, of which the following is a specification.

Myinvention relates tometallicburrsordisks for grinding corn or other substances; and it consists chiefly in arranging the metallic blades in parallel groups around the hub of the disk, the platform which carries the blades being for this purpose provided with several ribs running from the hub toward the circumference. The grinding-disks (millstones) are obtained by arranging round a hub or box alternate sheets of metal and of wood, so as to give them an inclination similar to that of the grooves of an ordinary millstone, and by bracing the whole together with a strong iron ring or rings laid on red hot. Each disk is then brought to the lathe for planing the surfaces and boring out the hub, after which the grooves are formed in the wood by a chisel, rasp, or other tool, so as to lay bare the edges of thesheets of metal ou the side where they are intended to cut. The grooves may run right or left, according to the motion of the driving-shaft, and they are made deeper in the center than toward the circumference of the disk. In order to diminish the wear and tear in the center of the disk, plates of cast-iron may'be made to alternate with steel blades near the hub, while wood is used near the circumference. The depth of the grooves in the cast-iron may be rather more than half of the thickness of a grain, and beech- Wood is preferred for separating the metal blades. The fixed grinding-disk is preferably supported by a triangular plate resting on a tripod, which forms the frame of the mill, said plate supporting also the casing which surrounds the stones. The vertical driving-shaft which carries the revolving disk is supported by a step-bearing, which can be raised and lowered by one of the devices generally applied for raising and lowering millstones, in order to vary the distance between the disks.

Referring to the accompanying drawings, which illustrate my invention, Figure lis partly a vertical section and partly an elevation of a llower stone, and has at the top three ears, S

S, distributed equally over the circumference, for supporting the upper stone by means of three posts, O, provided with screwed ends. The cast-iron plate C, holding together the pieces which constitute the upper burr, has

three corresponding ears, H, through which pass the upper ends ofthe bolts S. A ring, R, of angle-iron serves as a cover for retaining the flour or other ground material. The pieces constituting the lower burr are likewise held together by a cast-iron plate cast in one piece with the hub, and provided at its circumference with wings D, which project into the grooveE and take the product tothe dischargeopening. The nave of the lower burr is secured to the driving-shaft P by three keys, and on the end of the shaft is screwed a nut, N, which is conoidal and serrated on its circumference in order to take part in the grinding action. Fig. 4 shows this nut detached from the shaft.

The construction of thelburrs is shown in detail by Figs. 2 and 3. They are built by filling every sector formed by the ribs r r of the platform with steel blades s and cast-iron or wooden packing-plates p, placed vertically and alternating with each other, by subsequently binding these plates firmly together by one or two wrought-iron rings laid on hot, and then turning the burr in the lathe, after which the surface of the'packing-plates is grooved out by the file or file and chisel, so as to produce a radial groove between any two contiguous cutting-blades, which groove has about half the depth of a grain of corn if used for grinding corn. The ribs r r, preferably eight in number and cast tothe platform, are tangential to the circular opening o, through which the raw material is introduced. These ribs may reach to the circumference of the burr, or they may only occupy a part of itsradial width.

By this apparatus the finest grain may be ground, as well as phosphates, or even stones. For the latter materials it is necessary to make the intermediate or packing pieces between the blades of a hard material and the blades ot' steel from the central opening to the circumference ot' the disk. The'grinding action is effected by the metallic blades, which extend nearly radially from the center toward the circumference, the intermediate pieces of wood or ot' cast-iron which separate the blades from each other serving to hold the grain durvented by others; but in those which most rex semble my construction the cutting-blades and filling-pieces are only held together by setscrews, the tillingpieces are wedge-shaped, and the blades extend to the central opening, whereas in my improved burr every series of blades and filling-pieces is held in a sector lmited by cast-iron ribs, and every fillingplate has two parallel faces, except one in every section, which serves as a wedge for the whole section; The whole is held together by a ring laid on hot, and which, in cooling, gives to the disk the rigidity necessary for dressing the surface and for turning ont good work.

What I claim as my invention is A metallic grinding-disk consisting of a bottom plate provided 4with a nave, vertical ribs attached to said nave and bottom plate, and extending from the interior toward the circumference of the disk, cutting-blades, packingblades or filling-pieces placed between the cutting-blades, and a wrought-iron ring or rings for holding the cutting-blades and packingpieces in the requisite position, substantially as described andiillustrated.

In testimony whereot` I have signed this specification in the presence of two subscribing witnesses.

PIERRE TANVEZ. Witnesses:

Vrcron OLGIATO, PIERRE OLIN. 

